The link is there, folder — no. What is it?

Hello.
Is there a website. You have access via FTP.
And there is a link - for example, site.ru/xxx - the browser sees and displays the page as usual.
But the folders xxx absolutely no.
How to find out what the server is doing in this query as it builds the page, and so on?
June 14th 19 at 20:55

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